1. Field of the Invention
The present invention relates to peripheral cards for computer systems. More specifically, the present invention implements a method and apparatus for reliable extraction of thin form factor computer cards from a computer system.
2. Art Background
It is quite common for computer systems, notably notebook computers, to have a slot into which may be inserted a thin form factor memory cartridge. A "memory cartridge" is a plug-in module containing random access memory (RAM) chips that can be used to store data or programs. Memory cartridges are used primarily in portable computers as smaller, lighter, substitutes for disk drives. Memory cartridges typically use a nonvolatile form of RAM which does not lose its contents when power is turned off, or battery-backed RAM, which maintains its contents by drawing current from a rechargeable battery within the cartridge.
To encourage the development of memory cartridges, various standards have been established. One such standard was established by the Personal Computer Memory Card Industry Association (PCMCIA). However, other standards exist, for example, in Japan, JEIDA is the equivalent association to PCMCIA.
The PCMCIA PC Card Standard 2.0 outlines the architecture and specifications for an interchangeable integrated circuit card, with both data storage ("memory") and peripheral expansion ("I/O") card types defined. Cards, which conform to the PCMCIA Standard 2.0, interface through a standard 68-pin connector to operate interchangeably in the same 68-pin slot of a host computer system.
However, the PCMCIA standard, by itself, does not guarantee interoperability. While the PCMCIA standard establishes some electrical and software requirements, these requirements are not stringent enough to guarantee that a PCMCIA card will function properly in every manufacturer's PCMCIA slot. Primarily, the PCMCIA standard defines physical specifications for an interchangeable card. For example, PCMCIA Standard 2.0 specifies that the width and length of a card must be exactly the same size as that of a credit card. Furthermore, while the thickness is specified to be 130 thousandths of an inch (3.3 millimeters) along the edge of the card, the center area of the card is allowed to have a maximum thickness of 197 thousandths of an inch (5 millimeters).
Because of the small size and light weight of PCMCIA cards, they are quite popular and a variety of PCMCIA Standard 2.0 card devices are now, or will soon be, available. Examples of PCMCIA card devices include memory devices such as RAM, dynamic RAM (DRAM), and flash memory storage products. Examples also include I/O devices such as modem, facsimile (fax), local area network (LAN), small computer system interface (SCSI) and wireless I/O cards. Significant numbers of computers which have PCMCIA card slots, as well as, significant numbers of the cards themselves, have been manufactured. These computer systems and cards are either on the market, or have already been sold. Furthermore, it is anticipated that many more such computer systems and cards will ultimately be manufactured and sold.
Cards built according to the PCMCIA PC Card Standard 2.0 have a propensity to jam the card slot of a computer system when an ejection of the card from the card slot is attempted. Usually, when a card jams a card slot, the computer system must be disassembled by a qualified technician to extract the jammed card. At best, a jammed card degrades the utility of the computer system. At worst, a card jammed in a slot will either ruin the computer system, or render the system unusable.